db410c: automatically launch fastboot

If during boot the key-vol-down press is detected
we'll fall back to fastboot.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>

board/qualcomm/dragonboard410c/dragonboard410c.c

@@ -140,7 +140,8 @@ int misc_init_r(void)
 
 	if (dm_gpio_get_value(&resin)) {
 		env_set("bootdelay", "-1");
-		printf("Power button pressed - dropping to console.\n");
+		env_set("bootcmd", "fastboot 0");
+		printf("key_vol_down pressed - Starting fastboot.\n");
 	}
 
 	return 0;